API Checks

API Checks go beyond simple HTTP monitoring by letting you define multi-step sequences of HTTP requests with complex assertions. Test authentication flows, CRUD operations, and API contracts in production.

Plan requirement: OPS and above.

HOW IT WORKS

An API Check is an ordered sequence of steps. Each step makes an HTTP request and validates the response against one or more assertions. Variables can be extracted from responses and used in subsequent steps.

Step 1: POST /auth/login → extract token
Step 2: GET /api/resources (with token) → assert 200 + JSON schema
Step 3: DELETE /api/resources/:id → assert 204

STEP CONFIGURATION

Each step supports:

Field	Description
name	Step label for reporting
method	HTTP method
url	Full URL (supports ${variable} interpolation)
headers	Request headers (supports variables)
body	Request body (supports variables)
timeout	Per-step timeout in ms (default: 10000)
assertions	Array of assertion rules
extractions	Variables to extract from the response

7 ASSERTION TYPES

Type	Description	Example
status_code	HTTP status code check	Equals 200
response_time	Total response duration	Under 1500ms
header	Response header value	Content-Type contains json
body	Raw body string match	Contains "success"
json_path	JSONPath expression match	$.data.id is not empty
regex	Regex pattern against body	Matches "token":"[a-f0-9]{32}"
body_size	Response body size	Under 50KB

VARIABLE EXTRACTION

Extract values from responses to use in subsequent steps:

{
  "extractions": [
    {
      "name": "auth_token",
      "source": "body",
      "path": "$.token"
    },
    {
      "name": "resource_id",
      "source": "body",
      "path": "$.data[0].id"
    },
    {
      "name": "request_id",
      "source": "header",
      "header": "X-Request-Id"
    }
  ]
}

Use extracted variables with ${variable_name} syntax:

{
  "headers": {
    "Authorization": "Bearer ${auth_token}"
  },
  "url": "https://api.acme.com/resources/${resource_id}"
}

FULL EXAMPLE

{
  "name": "User CRUD Flow",
  "steps": [
    {
      "name": "Authenticate",
      "method": "POST",
      "url": "https://api.acme.com/auth/login",
      "headers": { "Content-Type": "application/json" },
      "body": "{\"email\":\"test@acme.com\",\"password\":\"${TEST_PASSWORD}\"}",
      "assertions": [
        { "type": "status_code", "operator": "equals", "value": 200 },
        { "type": "json_path", "path": "$.token", "operator": "not_empty" }
      ],
      "extractions": [
        { "name": "token", "source": "body", "path": "$.token" }
      ]
    },
    {
      "name": "Create Resource",
      "method": "POST",
      "url": "https://api.acme.com/resources",
      "headers": {
        "Authorization": "Bearer ${token}",
        "Content-Type": "application/json"
      },
      "body": "{\"name\":\"Test Resource\"}",
      "assertions": [
        { "type": "status_code", "operator": "equals", "value": 201 },
        { "type": "response_time", "operator": "less_than", "value": 2000 }
      ],
      "extractions": [
        { "name": "resource_id", "source": "body", "path": "$.id" }
      ]
    },
    {
      "name": "Verify Resource",
      "method": "GET",
      "url": "https://api.acme.com/resources/${resource_id}",
      "headers": { "Authorization": "Bearer ${token}" },
      "assertions": [
        { "type": "status_code", "operator": "equals", "value": 200 },
        { "type": "json_path", "path": "$.name", "operator": "equals", "value": "Test Resource" }
      ]
    }
  ]
}

SCHEDULING

API Checks run on a configurable interval (minimum 60 seconds). Each execution runs the full step sequence. If any step fails, the check is marked as failed and subsequent steps are skipped.

Results include per-step timing, assertions results, and extracted variable values for debugging.